Ga-doped Pt-Ni Octahedral Nanoparticles as a Highly Active and Durable Electrocatalyst for Oxygen Reduction Reaction

Bimetallic PtNi nanoparticles have been considered as a promising electrocatalyst for oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs) owing to their high catalytic activity. However, under typical fuel cell operating conditions, Ni atoms easily dissolve into the electrolyte, resulting in degradation of the catalyst and the membrane-electrode assembly (MEA). Here, we report gallium-doped PtNi octahedral nanoparticles on a carbon support (Ga-PtNi/C). The Ga-PtNi/C shows high ORR activity, marking an 11.7-fold improvement in the mass activity (1.24 A mgPt-1) and a 17.3-fold improvement in the specific activity (2.53 mA cm-2) compare to the commercial Pt/C (0.106 A mgPt-1 and 0.146 mA cm-2). Density functional theory calculations demonstrate that addition of Ga to octahedral PtNi can cause an increase in the oxygen intermediate binding energy, leading to the enhanced catalytic activity toward ORR. In a voltage-cycling test, the Ga-PtNi/C exhibits superior stability to PtNi/C and the commercial Pt/C, maintaining the initial Ni concentration and octahedral shape of the nanoparticles. Single cell using the Ga-PtNi/C exhibits higher initial performance and durability than those using the PtNi/C and the commercial Pt/C. The majority of the Ga-PtNi nanoparticles well maintain the octahedral shape without agglomeration after the single cell durability test (30,000 cycles). This work demonstrates that the octahedral Ga-PtNi/C can be utilized as a highly active and durable ORR catalyst in practical fuel cell applications

Expression of GA733-Fc Fusion Protein as a Vaccine Candidate for Colorectal Cancer in Transgenic Plants

The tumor-associated antigen GA733 is a cell-surface glycoprotein highly expressed in colorectal carcinomas. In this study, 3 recombinant genes were constructed as follows: GA733 tagged to the ER retention sequence KDEL (GA733K), GA733 fused to the immunoglobulin Fc fragment (GA733-Fc), and GA733-Fc fused to the ER retention sequence (GA733-FcK). Agrobacterium-mediated transformation was used to generate transgenic plants expressing recombinant genes. The presence of transgenes was confirmed by genomic PCR. Western blot, confocal immunofluorescence, and sandwich ELISA showed the expression of recombinant proteins. The stability, flexibility, and bioactivity of recombinant proteins were analyzed and demonstrated through N-glycosylation analysis, animal trials, and sera ELISA. Our results suggest that the KDEL retained proteins in ER with oligomannose glycan structure and enhanced protein accumulation level. The sera of mice immunized with GA733-FcK purified from plants contained immunoglobulins which were at least as efficient as the mammalian-derived GA733-Fc at recognizing human colorectal cancer cell lines. Thus, a plant system can be used to express the KDEL fusion protein with oligomannose glycosylation, and this protein induces an immune response which is comparable to non-KDEL-tagged, mammalian-derived proteins

Craniopharyngioma in the Temporal Lobe: A Case Report

Herein, we report on an unusual case of craniopharyngioma arising in the temporal lobe with no prior history of surgery and with no connection to the craniopharyngeal duct. MR images showed a cystic tumor with a small solid portion. To the best of our knowledge, this is the first case of a craniopharyngioma occurring in the temporal lobe

Ga-doped Pt-Ni Octahedral Nanoparticles as a Highly Active and Durable Electrocatalyst for Oxygen Reduction Reaction

Bimetallic PtNi nanoparticles have been considered as a promising electrocatalyst for oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs) owing to their high catalytic activity. However, under typical fuel cell operating conditions, Ni atoms easily dissolve into the electrolyte, resulting in degradation of the catalyst and the membrane-electrode assembly (MEA). Here, we report gallium-doped PtNi octahedral nanoparticles on a carbon support (Ga-PtNi/C). The Ga-PtNi/C shows high ORR activity, marking an 11.7-fold improvement in the mass activity (1.24 A mgPt-1) and a 17.3-fold improvement in the specific activity (2.53 mA cm-2) compare to the commercial Pt/C (0.106 A mgPt-1 and 0.146 mA cm-2). Density functional theory calculations demonstrate that addition of Ga to octahedral PtNi can cause an increase in the oxygen intermediate binding energy, leading to the enhanced catalytic activity toward ORR. In a voltage-cycling test, the Ga-PtNi/C exhibits superior stability to PtNi/C and the commercial Pt/C, maintaining the initial Ni concentration and octahedral shape of the nanoparticles. Single cell using the Ga-PtNi/C exhibits higher initial performance and durability than those using the PtNi/C and the commercial Pt/C. The majority of the Ga-PtNi nanoparticles well maintain the octahedral shape without agglomeration after the single cell durability test (30,000 cycles). This work demonstrates that the octahedral Ga-PtNi/C can be utilized as a highly active and durable ORR catalyst in practical fuel cell applications

Oxygen-deficient triple perovskites as highly active and durable bifunctional electrocatalysts for oxygen electrode reactions

Highly active and durable bifunctional oxygen electrocatalysts have been of pivotal importance for renewable energy conversion and storage devices, such as unitized regenerative fuel cells and metal-air batteries. Perovskite-based oxygen electrocatalysts have emerged as promising nonprecious metal bifunctional electrocatalysts, yet their catalytic activity and stability still remain to be improved. We report a high-performance oxygen electrocatalyst based on a triple perovskite, Nd1.5Ba1.5CoFeMnO9-delta (NBCFM), which shows superior activity and durability for oxygen electrode reactions to single and double perovskites. When hybridized with nitrogen-doped reduced graphene oxide (N-rGO), the resulting NBCFM/N-rGO catalyst shows further boosted bifunctional oxygen electrode activity (0.698 V), which surpasses that of Pt/C (0.801 V) and Ir/C (0.769 V) catalysts and which, among the perovskite-based electrocatalysts, is the best activity reported to date. The superior catalytic performances of NBCFM could be correlated to its oxygen defect rich structure, lower charge transfer resistance, and smaller hybridization strength between O 2p and Co 3d orbitals

Whole-genome, transcriptome, and methylome analyses provide insights into the evolution of platycoside biosynthesis in Platycodon grandiflorus, a medicinal plant

Triterpenoid saponins (TSs) are common plant defense phytochemicals with potential pharmaceutical properties. Platycodon grandiflorus (Campanulaceae) has been traditionally used to treat bronchitis and asthma in East Asia. The oleanane-type TSs, platycosides, are a major component of the P. grandiflorus root extract. Recent studies show that platycosides exhibit anti-inflammatory, antiobesity, anticancer, antiviral, and antiallergy properties. However, the evolutionary history of platycoside biosynthesis genes remains unknown. In this study, we sequenced the genome of P. grandiflorus and investigated the genes involved in platycoside biosynthesis. The draft genome of P. grandiflorus is 680.1Mb long and contains 40,017 protein-coding genes. Genomic analysis revealed that the CYP716 family genes play a major role in platycoside oxidation. The CYP716 gene family of P. grandiflorus was much larger than that of other Asterid species. Orthologous gene annotation also revealed the expansion of beta -amyrin synthases (bASs) in P. grandiflorus, which was confirmed by tissue-specific gene expression. In these expanded gene families, we identified key genes showing preferential expression in roots and association with platycoside biosynthesis. In addition, whole-genome bisulfite sequencing showed that CYP716 and bAS genes are hypomethylated in P. grandiflorus, suggesting that epigenetic modification of these two gene families affects platycoside biosynthesis. Thus whole-genome, transcriptome, and methylome data of P. grandiflorus provide novel insights into the regulation of platycoside biosynthesis by CYP716 and bAS gene families

ENSO Atmospheric Teleconnections and Their Response to Greenhouse Gas Forcing

This is the final version of the article. Available from AGU via the DOI in this record.El Niño and Southern Oscillation (ENSO) is the most prominent year-to-year climate fluctuation on Earth, alternating between anomalously warm (El Niño) and cold (La Niña) sea surface temperature (SST) conditions in the tropical Pacific. ENSO exerts its impacts on remote regions of the globe through atmospheric teleconnections, affecting extreme weather events worldwide. However, these teleconnections are inherently nonlinear and sensitive to ENSO SST anomaly patterns and amplitudes. In addition, teleconnections are modulated by variability in the oceanic and atmopsheric mean state outside the tropics and by land and sea ice extent. The character of ENSO as well as the ocean mean state have changed since the 1990s, which might be due to either natural variability or anthropogenic forcing, or their combined influences. This has resulted in changes in ENSO atmospheric teleconnections in terms of precipitation and temperature in various parts of the globe. In addition, changes in ENSO teleconnection patterns have affected their predictability and the statistics of extreme events. However, the short observational record does not allow us to clearly distinguish which changes are robust and which are not. Climate models suggest that ENSO teleconnections will change because the mean atmospheric circulation will change due to anthropogenic forcing in the 21st century, which is independent of whether ENSO properties change or not. However, future ENSO teleconnection changes do not currently show strong intermodel agreement from region to region, highlighting the importance of identifying factors that affect uncertainty in future model projections.S. W. Y. is supported by the KoreaMeteorological Administration Researchand Development Program under grant KMIPA2015-2112. Wenju Cai is supported by Earth System and Climate Change Hub of the Australia National Environmental Science Programme, and Centre for Southern Hemisphere Oceans Research, an international collaboration between CSIRO and Qingdao National Laboratory for Marine Sciences and Technology. B. Dewitte acknowledges supports from FONDECYT(1151185) and from LEFE-GMMC. Dietmar Dommenget is supported by ARC Centre of Excellence for Climate System Science (CE110001028)

Putaminal Hypointensity in the Parkinsonian Variant of Multiple System Atrophy: Simple Visual Assessment Using Susceptibility-Weighted Imaging

Background and Purpose Susceptibility-weighted imaging (SWI) has been shown to be superior in its ability to demonstrate brain mineralization than other conventional MR imaging. The goal of our study was therefore to assess the frequency and extent of putaminal hypointensity in parkinsonian variant MSA using SWI. Methods 11 patients with multiple system atrophy-parkinsonian type (MSA-p), 30 patients with Parkinson’s disease (PD), and age matched 30 controls were investigated using 3 Tesla MRI. The pattern of putaminal hypointensity was measured using a visual grading scale and scored from 0 to 3. Results Hemi- or bilateral putaminal hypointensity (a score of ≥ 2) and hyperintense rim were recognized in 81.8% and 54.5% of 11 MSA-p, respectively. The scores of putaminal hypointensity of MSA-p were significantly higher than other groups (p < 0.001), a score of ≥ 2 differentiated MSA-p from other groups. And all five patients with early disease stage also showed these characteristic findings. Conclusions SWI appears to be useful for depicting putaminal hypointensity even in early stage of MSA-p. This finding suggests that iron deposition associated putaminal degeneration can occur early in the disease process